Rotaviruses are the most common etiological agents of diarrhea in infants and young children worldwide. Globally, each year 352,000-592,000 deaths in children less than 5 years of age can be linked to rotavirus infection. In addition, human caliciviruses are responsible for over 80% of nonbacterial gastroenteritis outbreaks affecting all age groups and up to 20% of sporadic acute gastroenteritis episodes in children. It was established by our group and others that in colonies with captive non-human primates (NHP), diarrhea is the leading cause of animal morbidity requiring veterinary care. Acute diarrhea in particular is one of the underlying clinical signs of enteritis that is, in general, associated with a variety of different causes that include, A) presence of infectious pathogens, B) incompatible dietary components, and C) management and social factors. This proposed study focuses on the first category concerning rotaviruses and enteric caliciviruses since we have evidence that these infections are endemic in primate colonies, and at the same time they go beyond what is routinely examined by diagnostic laboratories. As the success of the rhesus macaque model of human disease have resulted in increased use of disease- and genetically-defined animals, the demand for healthy macaques has reached critical proportions. Diagnostic survey and basic research studies with focus on viral causes of gastrointestinal (GI) diseases have not only potential to improve the quality of non-human primate research resource but mainly provide knowledge for development of new models of human disease. To accomplish these goals, we are proposing the following aims: Aim 1: Determine the prevalence of rotaviruses and enteric caliciviruses that are associated with GI disease in the TNPRC breeding colony rhesus macaques. Aim 2: Experimentally reproduce symptomatic rota- and calicivirus infection in seronegative rhesus macaques. In summary, we believe that proposed study will generate information about prevalence, demographics and immunologic surrogates of rota- and calicivirus infections in primates. Generated knowledge will be instrumental for development of novel primate models of human disease since both rotaviruses and enteric caliciviruses are established pathogens of humans. PUBLIC HEALTH RELEVANCE: Rotaviruses are the most common etiological agents of diarrhea in infants and young children worldwide. Globally, each year 352,000-592,000 deaths in children less than 5 years of age can be linked to rotavirus infection. In addition, human caliciviruses are responsible for over 80% of nonbacterial gastroenteritis outbreaks affecting all age groups and up to 20% of sporadic acute gastroenteritis episodes in children. It was established by our group and others that in colonies with captive non-human primates (NHP), diarrhea is the leading cause of animal morbidity requiring veterinary care. Acute diarrhea in particular is one of the underlying clinical signs of enteritis that is, in general, associated with a variety of different causes that include, A) presence of infectious pathogens, B) incompatible dietary components, and C) management and social factors. This proposed study focuses on the first category concerning rotaviruses and enteric caliciviruses since we have evidence that these infections are endemic in primate colonies, and at the same time they go beyond what is routinely examined by diagnostic laboratories. As the success of the rhesus macaque model of human disease have resulted in increased use of disease- and genetically-defined animals, the demand for healthy macaques has reached critical proportions. Diagnostic survey and basic research studies with focus on viral causes of gastrointestinal (GI) diseases have not only potential to improve the quality of non-human primate research resource but mainly provide knowledge for development of new models of human disease. Our goal is therefore two-fold: A) From the resource improvement perspective, proposed study will generate information about prevalence, demographics and immunologic surrogates of above viral infections in primates;B) Generated knowledge will be instrumental for development of novel primate models of human disease since both rotaviruses and caliciviruses are established pathogens of humans.